Biometria, conservação de germoplasma e multiplicação in vitro de jequitibás-rosa do Sul de Minas Gerais

Abstract

The jequitibá-rosa (Cariniana legalis (Mart.) O. Kuntze), 30 to 50m high is one of the largest native trees in Brazil. This species suffers from habitat fragmentation and is included in the list of endangered species in the vulnerable category. Occurs in a limited number of natural habitats, with a population density of <1 tree / hectare in the remaining fragments. The objective of this study was to micropropagate in vitro jequitibás-rosa of the south of Minas Gerais, as well as to conserve the germplasm, to make the establishment in vitro, acclimatization and the biometry of these. The tree climbing technique was used to collect explants, seeds and perform biometrics. For the in vitro micropropagation, the nodal segments were inoculated in WPM medium with different concentrations of ANA and BAP. For germination the seeds after disinfestation were immersed in distilled water at different times. After immersion, these were inoculated in MS medium supplemented with different concentrations of GA3. The plants obtained were acclimatized in pots of 550 cm3 containing the different substrates: vermiculite and forest soil; being later covered with a pet-type bottle to avoid dehydration. For callus induction, stem segments and cotyledons were inoculated in WPM medium at different concentrations of ANA and BAP. During the collection of the explants, two snakes were recorded in the jequitibá-rosa, being carried out photographs and biometrics of the same. In the experiments carried out there were no shoots in nodal segments of Cariniana legalis, at 90 days of cultivation. The best treatment for germination was the one in which the seeds were immersed in water 48h combined with 14.45 μM GA3, obtaining 70% of the seeds germinated. The acclimatized plants on substrate forest soil at 120 days presented the highest percentage of aerial part increase 103.08%; Number of leaves 282.36% and diameter 93.76% than those acclimatized in vermiculite. Callus induction (70%) and fresh mass increase (122%) were more efficient in WPM medium containing 0.54 ANA + 6.66 μM BAP. It was described an agonistic encounter between two individuals of Spilotes pullatus at 31m height in the crown of the jequitibá-rosa, this being the first record. The jequitibás-rosa have biometrics: DAP between 1.51 m and 2.80 m; Total height between 35,70 m and 50,00 m; ages between 330 and 611 years. For callogenesis induction in Cariniana legalis it is recommended to use cotyledonary explants cultivated in WPM medium, plus 30 g L-1 sucrose and added with 0.54 μM ANA + 6.66 μM BAP. In this way it was possible to establish in vitro the Jequitibá-rosa, the conservation of its germplasm in the form of callus, the production of plants after acclimatization, and besides the first report of the caninana snakes in greater height.